#include <stdio.h>

typedef struct Alumno Alumno;

struct Alumno{
    size_t age;
    Alumno *p_sig;
};

int main(void)
{
    Alumno a = {
        .age = 20,
    }, b = {
        .age = 21,
        .p_sig = NULL,
    };
    a.p_sig = &b;
    for(Alumno *p = &a; p; p = p->p_sig)
        printf("%ld\n", p->age);
}
